#include <NewPing.h>
#define TRIGGER_PIN  11  // Arduino pin tied to trigger pin on the ultrasonic sensor.
#define ECHO_PIN     10  // Arduino pin tied to echo pin on the ultrasonic sensor.

int length_of_the_track = 51;

NewPing sonar(TRIGGER_PIN, ECHO_PIN, length_of_the_track); // NewPing setup of pins and maximum distance.


void setup() {
  Serial.begin(9600); // Open serial monitor at 115200 baud to see ping results.
}

void loop() {
  //distance
  delay(1000);// Wait 50ms between pings (about 20 pings/sec). 29ms should be the shortest delay between pings.
  Serial.print("ditance between the cars & track: ");
  Serial.println(sonar.ping_cm());// Send ping, get distance in cm and print result (0 = outside set distance range)
  float dis = sonar.ping_cm();
  //distance between the cars and the track
  Serial.print("distance of the line: ");
  Serial.println(length_of_the_track-dis);
  // no of cars
  float avg_length_of_a_car = 7.125;
  float cars = ceil((length_of_the_track-dis)/avg_length_of_a_car);
  Serial.print("number of cars: ");
  Serial.println(cars);
  //Time taken by the cars to take a right turn
  int avg_time = 4;// Actually the time for one car is 5s, for two 6 second, That's why the equation becames n+4 s, where n = the no of cars
  int time_taken = cars+4;
  Serial.print("Time taken for a car: ");
  Serial.println(time_taken);
  Serial.println("----------------------------------------");
}